Validating AIM-Based Instrumentation and Associated Measurement Techniques - Good Cascade Impactor Practices, AIM and EDA for Orally Inhaled Products - page 341

Fig. 10.68 “Short stack” arrangement of Horodnik et al . [ 60 ] in which they reconfigured a full-
resolution ACI such that the back-up filter is located immediately below stage 1, and the other
stages are retained ( From [ 60 ]— used with permission )

for DPI testing where the total dead space in the measurement system is important,
such an arrangement may not be effective if used in connection with the evaluation
of pMDIs containing low-volatile cosolvent. Under such circumstances, it would
be more appropriate to locate one or more redundant stages (i.e . , not containing a
collection surface) before the size-fractionating stage, as was done by Mitchell
et al . [ 20 ], to ensure that cosolvent evaporation in the reduced system matched that
of the full-resolution CI.

10.10 AIM-Based Measurement Equipment: Learning from

Validation Studies, Current Status, and Future Needs

In December 2010 a workshop was organized by EPAG to act as a forum for the
discussion of ways to develop AIM-based apparatus toward maturity, given the
large amount of experimental data presented in the preceding sections of this
chapter in support of their adoption [ 61 ]. In the panel discussion that followed,